01/02/2007 1:00AM

Two more positive herpes tests


ALBANY, Calif. - Two additional horses in trainer Lloyd Mason's barn at Golden Gate Fields have tested positive for the equine herpesvirus, but they are showing no symptoms of the disease, said the California Horse Racing Board's equine medical director, Dr. Rick Arthur, on Tuesday. They are the second and third horses to test positive for equine herpes at Golden Gate. No horse outside of the Mason barn has tested positive.

Dr. Arthur called the test results "not terrible, but not great."

A horse trained by Mason tested positive for herpes last week, and Golden Gate, Bay Meadows, and Pleasanton were placed under quarantine last Friday. Horses at Bay Meadows and Pleasanton can ship into Golden Gate, which is conducting a race meet, but they can't go anywhere else. The quarantine is expected to last for at least 10 days, Arthur said. No horse outside the Mason barn has tested positive for the disease, which carries flu-like symptoms, including fever or respiratory infection, and can prove fatal in extreme cases.

The herpes tests were conducted at the University of California at Davis. Herpes is a contagious disease, and Arthur said horses can spread the disease for 10 days to two weeks.

One of the latest horses to test positive may be the original source of the disease, Arthur said. The horse, stabled adjacent to the Mason trainee who tested positive last week, had been running a temperature for several days, Arthur said.

University veterinarians are running tests on all the horses in Mason's barn and others in adjacent barns.

Mason's horses were allowed to work Monday for the first time since the quarantine began, coming to the track after 10 a.m. when all other horses had finished working. All of Mason's horses were scratched from last weekend's races, but he was allowed to enter horses for Friday's card.

Golden Gate Fields is disinfecting its starting gate before each race and disinfecting and replacing all bedding in holding barns for shippers from Pleasanton and Bay Meadows.